screw loctight, use plumbers thread sealant on the lim bolts so they dont leak in the future. same stuff you should have put on the 4 long bolts on the water pump.
and de grease your engine before you start to work on it.
when you did the water pump, did you bleed the air from the t stat housing when you re filled it with coolant? if not that could cause the hotter temps.
and it sounds like you have a vac leak if the idle is surging (rise and fall of rpm's.) check the T under the snout, they like to just break on their own for no reason.
